Farmer Brown has endured a lot in Cronin and Lewin’s Click, Clack, Moo series, and in this sixth book, he’s up against a holiday he hates, Halloween: “Witches give him nightmares. Pirates give him shivers.” He’s in the minority on the farm, though, as the sheep, mice, chickens, and more don costumes for a barn party. And who exactly is that “dark creature standing beneath the trees,” with a vampire cape and an orange bill? Cronin makes delicious use of onomatopoeia and repetition to generate eerie tension, and Lewin’s moonlit watercolors add just the right touch of spookiness. Ages 3–7. Agent: Holly McGhee, Pippin Properties. (Aug.)